1. Field of the Invention
The present invention relates to a socket-type multipolar electrical connector to be used together with its counter connector or plug-type multipolar electrical connector, and more particularly to a socket-type multipolar electrical connector in which, without hindrance for various types of signal processings, the pitch between each adjacent contact piece of a plurality of contact pieces is minimized to miniaturize the connector with the density of the contact pieces increased, so that the connector can be mounted directly on a printed circuit board.
2. Description of the Prior Art
When a socket-type multipolar electrical connector is used together with its counter connector or plug-type multipolar electrical connector in which all the terminal pins are arranged in a predetermined assembly pattern with a high density, the socket-type multipolar electrical connector is such that all the contact pieces thereof corresponding to the terminal pins are also arranged in the same assembly pattern with a high density.
There is conventionally known a socket-type multipolar electrical connector capable of satisfying the requirement mentioned above, which has contact piece groups comprising a plurality of contact pieces all of which are assembled with the body of the connector with the horizontal pitch between each adjacent contact piece being fine.
On the other hand, it is recently required to execute a variety of signal processings using a composite cable in which a braided shell shield surrounds various types of conductors (core wires, twisted wires and the like) having different diameters.
When a plug-type multipolar electrical connector is used satisfying the requirement mentioned above, i.e., an electrical connector of the type mentioned earlier in which all the terminal pins are arranged in a predetermined assembly pattern with high density, a problem arises in that it becomes difficult to provide the space necessary for connecting (by soldering or calking) the respective conductors of the composite cable to the respective terminal pins. The same problem also resides in a socket-type multipolar electrical connector.
There is known the technique discussed in Japanese Utility Model Application No. 4-15664, which corresponds to copending commonly owned copending application, Ser. No. 08/022,318, filed Feb. 23, 1993. This technique relates to a plug-type multipolar electrical connector which facilitates the wire handling of connecting the respective conductors having different diameters of a composite cable to respective terminal pins, yet enabling the electrical connector to be miniaturized with the density of the terminal pins increased. More specifically, this plug-type multipolar electrical connector is arranged such that the terminal pins are divided into a terminal pin group for thin conductors and a terminal pin group for thick conductors, the horizontal pitch between each adjacent terminal pin of the terminal pin group for thin conductors is fine, the horizontal pitch between each adjacent terminal pin of the terminal pin group for thick conductors is coarse. The terminal pin group for thin conductors is disposed at the center of the body made of an insulating material, and the terminal pin group for thick conductors is disposed at a lateral side of the terminal pin group for thin conductors.